Theory and Experiment: The Synthesis and Drug Application of “On-Off-On” Fluorescent Probes for Copper and Biothiols Detection

Abstract

Abnormal copper ions (Cu2+) and biothiols have potential impacts on environmental pollution and human health, so the detection of these substances with high selectivity and sensitivity has become an important research topic. In this study, we designed and synthesized two fluorescent probes (L1 and L2) based on naphthalene and anthracene derivatives that could specifically detect Cu2+ and biothiols. Two probes both showed excellent selectivity and sensitivity for Cu2+. Owing to the paramagnetic effect of Cu2+, the strong fluorescent intensity was quenched after the addition of Cu2+. When biothiols were added to the solution (L-Cu2+), the fluorescence intensity was significantly enhanced and recovered. So, the interaction process was accompanied with “ON-OFF-ON” phenomenon in fluorescent intensity. Two complexes (L-Cu2+) both showed low limit of detection for biothiols and weak cytotoxicity. Theoretical investigation analysis revealed that the intramolecular hydrogen bond existed in the structure of probes and the roles of molecular frontier orbitals in molecular interplay. In addition, two probes also showed good applicability in actual drug Atomolan. Therefore, two probes have the real application value in the detection of Cu2+, biothiols and drug efficacy in various environments.

Keywords: Fluorescent probe, Copper ion, Biothiol, Atomolan, Theoretical investigation, Drug application